80 lines
2.9 KiB
Go
80 lines
2.9 KiB
Go
/*
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Copyright 2022 The Karmada Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package client
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import (
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"context"
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"fmt"
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"net"
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corev1 "k8s.io/api/core/v1"
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apierrors "k8s.io/apimachinery/pkg/api/errors"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/util/intstr"
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"k8s.io/client-go/kubernetes"
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)
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// ResolveCluster parses Service resource content by itself.
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// Fixes Issue https://github.com/karmada-io/karmada/issues/2487
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// Modified from "k8s.io/apiserver/pkg/util/proxy/proxy.go:92 => func ResolveCluster"
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func resolveCluster(kubeClient kubernetes.Interface, namespace, id string, port int32) ([]string, error) {
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svc, err := kubeClient.CoreV1().Services(namespace).Get(context.TODO(), id, metav1.GetOptions{})
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if err != nil {
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if apierrors.IsNotFound(err) {
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/*
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* When Deploying Karmada in Host Kubernetes Cluster, the kubeClient will connect kube-apiserver
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* of Karmada Control Plane, rather than of host cluster.
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* But the Service resource is defined in Host Kubernetes Cluster. So we cannot get its content here.
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* The best thing we can do is just assemble hosts and ports according to a specific rule, and try to connect to them.
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*/
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return []string{
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net.JoinHostPort(fmt.Sprintf("%s.%s.svc.cluster.local", id, namespace), fmt.Sprintf("%d", port)),
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// To support the environment with a custom DNS suffix.
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net.JoinHostPort(fmt.Sprintf("%s.%s.svc", id, namespace), fmt.Sprintf("%d", port)),
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}, nil
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}
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return nil, err
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}
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if svc.Spec.Type != corev1.ServiceTypeExternalName {
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// We only support ExternalName type here.
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// See discussions in PR: https://github.com/karmada-io/karmada/pull/2574#discussion_r979539389
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return nil, fmt.Errorf("unsupported service type %q", svc.Spec.Type)
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}
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svcPort, err := findServicePort(svc, port)
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if err != nil {
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return nil, err
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}
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if svcPort.TargetPort.Type != intstr.Int {
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return nil, fmt.Errorf("ExternalName service type should have int target port, "+
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"current target port: %v", svcPort.TargetPort)
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}
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return []string{net.JoinHostPort(svc.Spec.ExternalName, fmt.Sprintf("%d", svcPort.TargetPort.IntVal))}, nil
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}
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// findServicePort finds the service port by name or numerically.
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func findServicePort(svc *corev1.Service, port int32) (*corev1.ServicePort, error) {
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for _, svcPort := range svc.Spec.Ports {
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if svcPort.Port == port {
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return &svcPort, nil
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}
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}
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return nil, apierrors.NewServiceUnavailable(fmt.Sprintf("no service port %d found for service %q", port, svc.Name))
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}
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